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Biochar as a soil amendment recently take special attention for ameliorating salt-affected soils, whereas it can be an agriculturally important resource for increasing soil fertility and productivity through the ameliorating of salt-affected soils. The experimental field was conducted in 2013–2014 and 2014–2015 growing season for maize in saline–sodic soil at Agricultural Faculty Farm, Tanta University. The objectives of this study were (i) to study the reclamation effectiveness of wood sawdust (BW) and maize stalk biochars (BM) at rates of 5, 10, and 19 ton ha−1 on amelioration of a saline sodic soil; (ii) evaluation of the response of maize (Zea mays L.) crop and plant nutrients uptake to different treatments; and (iii) monitoring of the gradual improvement in saline sodic soil chemical properties. The results indicated that biochar application significantly increased soil organic matter (SOM), microbial biomass (C), cation exchange capacity (CEC), exchangeable cations, available phosphorus concentration, fertility index but decreased electrical conductivity (EC), and exchangeable sodium percentage (ESP) of the studied soil. The treatment of 19 ton ha−1 of wood sawdust biochar showed the highest decreases in EC by 62.0%, ESP by 74.5%, and exchangeable Na by 67.4% relative to the control. The highest significant increase in the uptake of NPK, grain, and straw yield of maize plants and soil fertility index corresponded to the 19 ton ha−1 wood sawdust biochar treatment. Our results indicate that biochar can ameliorate saline–sodic soils and improve soil fertility.

The application of soil amendments to immobilize heavy metals is a promising technology to meet the requirements for environmentally sound and cost-effective remediation. The present study was carried out to evaluate the result of phosphogypsum (PG) used alone and in combination with compost (CP) at a mix ratio of 1:1 wet weight ratio (PG + CP) at 10 and 20 g dry weight kg−1 dry soil, on heavy metal immobilization in contaminated soil and on canola growth. The results revealed that the Pb, Cd and Zn uptake of canola plants was reduced by the application of PG alone and when it was mixed with CP as compared with untreated soil. At an application rate of 10 g dry weight kg−1 dry soil of (PG + CP) the dry weight of canola plants increased by 66·8% was increased in comparison with its weight in the untreated soil. The addition of PG alone resulted in more pronounced immobilization of heavy metal as compared with PG mixed with CP. Plant growth was improved with CP addition, but heavy metals immobilization was the greatest in PG alone treatments. Results suggest that PG may be useful for the immobilization of heavy metals in contaminated soils. Copyright © 2014 John Wiley & Sons, Ltd.

The application of soil amendments to immobilize heavy metals is a promising technology to meet the requirements for environmentally sound and cost-effective remediation. The present work was carried out to evaluate the effect of phosphogypsum (PG) used alone and in combination with compost (CP) at a mix ratio of 1:1 wet weight ratio (PG+CP) at 10 and 20 g dry weight kg−1 dry soil, on heavy metal immobilization in contaminated soil, and on canola growth (Brassica napus). The results were then compared with untreated soil (control). The results revealed that the Pb, Cd, and Zn uptake of canola plants was reduced by the application of PG alone and when it was mixed with CP. At an application rate of 10 g dry weight kg−1 dry soil of (PG+CP), the dry weight of canola plants increased by 66.8%, which was increased in comparison on its weight in the untreated soil (control). The addition of PG alone resulted in more pronounced immobilization of heavy metals as compared to PG mixed with CP. Plant growth...

Composting allows simple management of animal manure but excessive aeration can increase emissions of polluting gases such as ammonia or nitrous oxide. The aim of the present work was to determine the effect of three techniques - turning, compacting and the addition of water - on gaseous emissions. One ton of cattle manure and 3 tons of turkey manure were composted in two and four cells for 46 and 51 days respectively. The manure was either turned, wetted, or compacted. Emissions of carbon dioxide, water vapor, ammonia and nitrous oxide were monitored. The results show that turning did not alter the free air space. Compacting can be used specifically to reduce the water loss. A reduction of free air space by 20-60%, either by compacting or adding water (or both), reduced the ammonia and nitrous oxide emissions by 30-70%. © 2006 Elsevier Ltd. All rights reserved.